Bug Description

To Reproduce

0. Close all existing nautilus/file manager instances.
1. Plug in a usb device that has one or more mountable drives.
2. Move the mouse over the launcher area
3. Click on the USB icon at the bottom of the Launcher

What currently incorrectly happens:
- Ever time you click on the USB Launcher icon a new window is spawned!

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Desired solution:

When the user clicks on the USB drive icon in the Launcher:

- If the USB drive window is in focus, nothing should happen. This is irrespective of whether there are any other Nautilus windows open.
- If the USB drive window is not in focus, it should be brought into focus
- If the user middle clicks on the USB drive window, a second window representing the USB drive should be created.
- If the USB drive window is in focus, and a second (or more) window(s) representing the USB drive is open, clicking on the USB launcher icon should trigger a spread of *just the USB* windows (excluding any Nautilus windows).

Note 1: any Nautilus window that is currently displaying the contents of the USB drive, is classified as representing the USB drive. This is irrespective of how the Nautilus window was opened.

Note 2: If there are two or more USB drives, the windows are associated with the USB drive they are currently displaying.

- automounted usb drives do not show the active glyph in launcher after- opening a nautilus window+ Launcher - automounted usb drives do not show the active glyph in+ launcher after opening a nautilus window